Headquartered in Washington, DC and playing home matches at RFK Stadium, D.C. United is the most successful professional soccer organization in the history of the United States. United is four-time MLS Cup Champions (1996, 1997, 1999 and 2004) and winners of the 1996 and 2008 U.S. Open Cup, the 1998 CONCACAF Champions Cup, the 1998 Interamerican Cup and the 1997, 1999, 2006 and 2007 MLS Supporters Shield.